Generally, tungsten inks, molybdenum inks or Mo-Mn inks have been used for forming metallized layers on ceramics, and particularly on alumina porcelains. Examples of metallizing processes include a process which comprises applying a metallizing ink to a green molding, namely, an unfired molding, and carrying out metallization simultaneously with the firing of the ceramic, and a process which comprises carrying out metallization on porcelains. The tungsten inks or the molybdenum inks generally has been used for the former, and the Mo-Mu inks generally has been used for the latter.
With respect to obtaining a desired resistivity of the conductor using such earlier metallizing tungsten ink or molybdenum ink, it is noted that the resistivity depends upon width, thickness, and length of the coated face. In ceramic multilayer distributing boards adopted for present high density apparatus, it is required that the width of metallized distributing line be 100 .mu.m or less. Further, it is required to form distribution coating lines having a thickness as thin as possible so as to form a smooth surface having a low degree of uneveness that 20 to 30 sheets on which distributing lines are formed can be superposed to produce a multilayer product, and thus the thickness of the distributing lines is 10 .mu.m or less. Under such requirements, it is difficult to obtain metallized conductors having a desired low resistance using the prior tungsten ink or molybdenum inks.